# What differences are there when modeling metal-organic-frameworks as isolated clusters or periodic solids?

Should I take MOF (metal-organic framework) as a periodic structure or an isolated cluster? What's the difference between them? If it's periodic, can I do an analysis of the electronic structure, such as band structure and density of states? If it's an isolated cluster, do I need to put a large vacuum along with the $$x$$, $$y$$, and $$z$$ directions? In essence, is there any difference between isolated clusters and periodic solid when modeling MOF structures?